Time switch



Oct. 12, 1943, T, G, TgGERsTEDT 2,331,639

TIME SWITCH Filed Sept. 16, 1942 Patented Oct. 12, 1943 TIME SWITCH TorGran Tigerstedt, Stockholm, Sweden, as-

signor to Aktiebolaget Esco Skandinaviska.

Companiet fr Utrikeshandel, Malmo, Sweden,

a corporation of Sweden Application September 16, 1942, Serial No.458,545 In Sweden June 11, 1942 Claims.

The present invention relates to time switches of the type wherein anelectrical circuit is closed by relative movementl of a contact pin orthe like and a perforated disc covering a contact surface. The inventionis particularly characterized by the feature that the said relativemovement is composed of two different movements, one of which is acircling movement and the other of which is a movement occurringcrosswise to the circling movement.

The object with this arrangement is that the contact pin shall alwaysdescribe a new path upon the perforated disc and thus not move along thesame path as before after the elapse of twenty-four hours. According tothe invention it is possible by means of a single perforated disc tocontrol switchings at any desired hour during long periods, for instanceone or more weeks. The device is primarily intended as an automaticswitch for radio receivers for which the entertainment schedules aregenerally published one week in advance. It is the intention thatunperforateddiscs shall be supplied so that the owner of a time switchconstructed according to this invention shall be able at the beginningof a new week to stamp out from the disc holes at the hours at which isdesired that the radio receiver shallbe automatically switched on.

The invention is described in the following with reference to theaccompanying drawing which shows diagramatically a preferred embodimentof the new time switch.

Numeral I designates a pointer shaft driven from the mechanism of aclock (not shown) which pointer shaft makes a complete revolution intwenty-four hours. The shaft I extends through a pinion 2 fastened to asuitable support so that it does not partake of the rotation of theshaft I. An arm 3 is mounted on the shaft I, and the free end of thisarm is provided with a slot, as shown at 4. In the slot a sliding block5 is movably mounted and this block carries a contact pin 6. In the arm3 bearings are provided for a shaft I upon which a gear 8 meshing withthe pinion 2 is fixed. The shaft I also carries a cam disc 9 having ahelical contour. The contact pin 6 is urged against the edge of this camdisc by means of a spiral spring I0 extending between the sliding blockand a xed point on the arm 3.

The contact pin 6 moves over a stationary metal plate II which iscovered by an insulating disc I2 of paper or other suitable materialprovided with a line-pattern and with suitable text, of which disc onlya fragment is shown. The

line-pattern on the paper disc consists of a helix or spiral-line I3arranged near the periphery of the disc and comprising eight fullwindings between which are formed seven narrow helical bands I4corresponding to the seven days of the week, further of twenty-fourradial lines I5 arranged at equal distances and corresponding to thehours of the day, and nally of radial tenminutes lines I6 arrangedbetween adjacent hourlines.

A contact spring I'I is shown bearing on the rotatable shaft I wherebyit is also electrically connected to the contact pin 6. From the contactspring II the circuit leads through a source of current I8 to anelectromagnetic relay I9 and from hence to the metal plate I I,

When the pointer shaft I of the time switch rotates in the clockwisedirection and turns the arm 3 so that the gear 8 performs a planetarymovement about the fixed pinion 2, the gear 8 and hence the cam disc 9will rotate in the clockwise direction about the shaft l. The speedratio is so chosen that the shaft I will make seven revolutions in thesame time as the shaft 'I makes one revolution. Since the contact pin 6is urged against the edge of the cam disc 9 by the spring I0, the saidpin will move in a helical path outwardly on paper disc I2 covering themetal plate I I in the space between the windings of the helix I3.

In the paper disc I2 apertures 2l) are made by means of a pair ofpunching-tongs, a stamp or other suitable tool in squares correspondingto the desired switching-on-times. In the drawing the apertures aremarked with black. In the embodiment shown apertures are made at thefollowing hours: Monday at 17.10, Wednesday and Thursday at 17.20 andFriday at 18.10. At these hours the contact pin 6 will contact the metalplate II and close the circuit through the relay IS so that the latteris actuated and in turn closes a circuit through the radio receiver (notshown) The relay I9 should preferably be of the type which after beingactuated by an electrical impulse from the source of current I8 remainsin the closed position until it is brought back by hand to the offposition.

The metal plate II should be arranged so as to be easy of access, forinstance by being removably mounted in the time switch or by beingmounted on a hinged nap or the like. Furthermore it should suitably beprovided with pins or other centering and orientating means for thepaper disc I2 which in turn should be provided with correspondingapertures for the pins so that it will always be fastened to the metalplate in the proper position. When the time switch is used for theswitching-on of a radio receiver it is intended that the owner of thetime switch at beginning of each week shall make holes in a paper discI2 corresponding to the hours of desired reception during the whole weekwhereafter the disc is fastened to the metal plate Il.

Other modifications are also possible.

What I claim and desire to secure by Letters Patent is:

1. In a time switch for automatic control of an electric circuit, acontact surface, a stationary perforated insulating member coveringsaidl contact surface, a rotatable arm, and a contact pin mounted forradial movement upon said rotatable arm.

2. In a time switch for automatic control of an electric circuit, acontact surface, a stationary perforated insulating disc covering saidcontact surface, a clock, a rotatable arm driven by said clock, acontact pin mounted for radial movement upon said rotatable arm, and acam member adapted to actuate said contact pin and to move the sameradially at the rotation of the rotatable arm.

said clock, a shaft carried by said rotatable arm,`

a cam disc having a helical contour mounted on said shaft, a gearmounted on the same shaft as the cam disc, a stationary pinion m'eshingwith said gear, and a contact pin. mounted for radial movement upon saidrotatable arm and adapted to be urged against the contour of said camdisc.

4. A time switch according to claim 3, wherein the contact surface isprovided with means for fastening the perforated insulating disc to thesame in a centered and oriented position.

5. In a time switch for automatic control of an electric circuit, acontact surface in said circuit, a perforated insulating sheet coveringsaid contact surface, means for closing said electric circuit through aperforation in said member, and means for producing a continuousrelative scanning movement in two co-ordinate directions between saidclosing means and said perforated member.

TOR GRAN TIGERSTED'I.

